This invention relates to a novel class of polymer/polyols, a process for preparing the same and their use in urethane elastomers and high resilience foams. More particularly, this invention relates to polyoxamate polymer polyols prepared by the condensation polymerization of an oxalate ester and a diamine directly in a polyether polyol.
Polymer/polyols are generally defined as stable dispersions of finely divided organic polymers in a polyol medium. The polymer/polyols are widely accepted by industry for this significant commercial utility in the preparation of various urethane elastomers and foams. At present four major classes of polymer/polyols are known.
The first class of polymer/polyols are characterized by having the dispersed phase based on vinyl polymerization. In this technology, the vinyl monomer (s) is polymerized in the polyol at elevated temperatures using an appropriate free radical initiator. As polymerization proceeds, the insoluble vinyl polymer precipitates from the system thereby generating the dispersion. Examples of this technology are found in U.S. Pat. Nos. 3,304,273 and 3,383,351.
A second class of polymer/polyols are characterized by having the dispersed phase based on the addition polymerizations of a diamine and a diisocyanate in a polyol. This technology results in a polyurea/polyol as described in U.S. Pat. No. 4,089,835.
A third class of polymer/polyols is characterized by having the dispersed phase based on the addition polymerization of a hydrazine and a diisocyanate. Typically an isocyanate is added to a solution of hydrazine in a polyol such that the equivalent ratio of NCO/NH.sub.2 is close to 1.0. A rapid reaction yields a dispersion of the polymer in the polyol. A more detailed description of this art is also found in U.S. Pat. No. 4,089,835.
Finally, the fourth class of polymer/polyols is characterized by having the dispersed phase based on a condensation polymerization of a nitrogen containing compound and a carbonyl compound. The condensation polymerization is allowed to occur directly in the polyol forming an aminoplast condensate dispersion. British Pat. Nos. 1,462,292 and 1,493,769 more fully describe this technology.
Despite the existence of this technology there is a continued need to explore alternative technologies which can improve the physical properties polymer/polyols lend to their products and to find more efficient methods for producing polymer/polyols. It is in the pursuit of these objectives that the present invention was discovered.